ESTRO 2020 Abstract Book

S118 ESTRO 2020

; 6 Klinikum Mutterhaus der Boromäerinnen, Department of Radiation Oncology-, Trier, Germany ; 7 University Hospital Magdeburg, Department of Radiation Oncology, Magdeburg-, Germany ; 8 Charité University Hospital, Department of Radiation Oncology, Berlin, Germany ; 9 Offenburg St. Josefsklinik, Department of Radiation Oncology, Offenburg, Germany ; 10 Helios University Hospital Wuppertal, Department of Nuclear Medicine, Wuppertal, Germany ; 11 Marienhospital Stuttgart, Department of Nuclear Medicine, Stuttgart, Germany ; 12 University Hospital Mainz, Department of Nuclear Medicine, Mainz, Germany ; 13 Helios Kliniken Schwerin, Department of Nuclear Medicine, Schwerin, Germany ; 14 Saarland University Hospital, Department of Nuclear Medicine, Homburg/Saar, Germany ; 15 University of Mainz, Institute of Medical Biostatistics- Epidemiology and Informatics, Mainz, Germany ; 16 University of Freiburg, Institute for Medical Biometry and Statistics, Freiburg, Germany ; 17 University of Freiburg - Medical Center, Department of Radiation Oncology, Freiburg, Germany Purpose or Objective The PET-Plan prospective multicentre two-arm randomised trial (NCT00697333) investigated the optimization of concurrent radiochemotherapy (RT) planning using 18F-FDG-PET in locally advanced non small cell lung cancer (NSCLC). Here, we analyze the influence of protocol adherence and radiotherapy quality on outcome. Material and Methods Radiotherapy quality assurance (RTQA) as part of the PET- Plan study protocol included pro- and retrospective review of RT plans and RT application by predefined criteria. Medical and physical aspects were reviewed by radiation oncologists and medical physicists (RTQA group), as well as mutually by study center members. After passing the initial prospective central review of the first cases per study center, the site qualified for mutual review executed during study group meetings, where RTQA review results were discussed in teaching sessions in order to continually improve protocol compliance. After the end of recruitment, all cases again underwent post-treatment review by the RTQA group. Overall, up to 24 items per plan were reviewed and categorized into protocol compliant, minor, non-therapy relevant major (MA) and therapy-relevant (MA+) deviations. Those items comprised delineation of target volumes (GTV of the primary tumor, CTVs (involved nodal stations: CTVesc; elective lymph nodes: CTVel, only in study arm A)), delineation and adherence to dose constraints of organs at risk (OAR: lung, esophagus, spinal cord and heart), RT dose escalation and specifications and RT execution. Results Individual data of 204 randomized patients were analyzed (Arm A: n=99, B: n=105). Overall, 173 (75%) patients had any MA and 31 (19%) any MA+. Most commonly, MA and MA+ were observed for: CTV delineation, OAR delination of heart and spinal cord, OAR doses to lung and spinal cord, total dose of escalation volume (PTV) and overall treatment time. In low volume centers (≤ 5 patients) there was a tendency for more MA+. Median follow-up time was 29 months. Patients with MA+ had an inferior overall survival (HR 2.9 [95% CI 1.8–4.4], p<.001) as well as a higher risk of locoregional progression (HR 5.7 [95% CI 2.7– 11.1], p<.001) as compared to patients without MA+ deviations.There was an unfavorable impact on overall survival by incorrect OAR delination and disregard of OAR dose constraints (HR 3.6 [95%CI 1.5-7.3], p 0.006) as well as by inadequate physical RT planning and RT execution (HR 2.4 [95%CI 1.4-3.8], p 0.003), whereas target volume delineation was without significant impact (HR 1.6 [95%CI 0.7-3.2], p 0.21). Conclusion

Secondary objectives were: incidence of dysphagia, duration of thoracic symptom response, QOL, toxicity, progression-free survival and overall survival. Material and Methods Patients 18 years or older, PS 0-1, Stage III or IV NSCLC with symptoms due to intrathoracic disease planned for HDPRT to achieve local control and symptom relief were eligible . Patients were randomised to 36Gy/12f versus 40Gy/20f with concurrent Cisplatin 20mg/m2 IV d1,8,15,22 and vinorelbine 25mg/m2 IV d 1,8,22 ( superior arm of TROG 03.07). The primary objective was assessed by comparing the mean change in Intrathoracic symptom burden index (ISBI, defined as the average of 4 components based on items from EORTC QLQ LC13) from baseline to 6 weeks from end of treatment between arms, using a linear regression model. Each of the four symptoms included in the index were assessed separately to assess relative relief, using the Cochran test for ordinal data from a 2x6 contingency table. The sample size of 130 patients was based on the ability to show a mean difference between arms of 10 points in the ISBI. Results The trial closed early due to slow accrual. 76 patients (60% Stage IV, 30% Stage III) were randomised. Symptoms included cough (60% ), dyspnoea (40%), haemoptysis (24% ) and pain (50%). The ISBI was significantly lower at 6 weeks compared with baseline in the entire cohort with no significant difference between trial arms. For the component symptoms, at 6 weeks there was a statistically significant improvement in cough, haemoptysis and chest pain compared with baseline but no difference between trial arms. For dyspnoea, there was no significant difference between baseline and 6 weeks or between trial arms. The median survival time for the entire cohort was 13.9m, median survival of 12.4m for HDPRT and 15m for C-HDPRT (ns). There was no difference in Grade 2 or higher oesophagitis between arms. The incidence of Grade 3 fatigue, neutropenia and anorexia were higher in the C-HDRT arm Conclusion The results are in agreement with 2018 ASTRO guideline recommending the administration of a platinum- containing doublet concurrently with moderately hypofractionated palliative RT in patients with Stage III NSCLC deemed unsuitable for curative therapy. This study demonstrates that this is a an acceptable approach in selected patients with Stage IV NSCLC. The results also provide rates of symptom relief achievable with modern palliative RT regimens. OC-0230 Soft tissue match and adaptive radiotherapy reduce incidence of radiation pneumonitis OC-0231 Outcome impact of radiotherapy protocol compliance: RTQA results from the PET-Plan trial T. Schimek-Jasch 1 , S. Kremp 2 , M. Stockinger 3 , A. Küsters 4 , T. Hehr 5 , Y. Bultel 6 , P. Hass 7 , J. Fleckenstein 2 , A.H. Thieme 8 , S. Adebahr 1 , E. Gkika 1 , V. Duncker-Rohr 9 , M. Tosch 10 , S.M. Eschmann 11 , M. Miederer 12 , G. Holl 13 , H.C. Rischke 1 , A. Schaefer-Schuler 14 , J. König 15 , C. Broichhagen 16 , S. Lenz 16 , H. Binder 16 , A. Grosu 17 , U. Nestle 4 1 University of Freiburg- Medical Center, Department of Radiation Oncology, Freiburg, Germany ; 2 Saarland University Hospital, Department of Radiation Oncology, Homburg/Saar, Germany ; 3 University Hospital Mainz, Department of Radiation Oncology, Mainz, Germany ; 4 Kliniken Maria Hilf, Department of Radiation Oncology, Mönchengladbach, Germany ; 5 Marienhospital Stuttgart, Department of Radiation Oncology-, Stuttgart, Germany Withdrawn from presentation